Laundry dryer drum with external surface cleaning means



May 13, 1969 F. w. GRANTHAM LAUNDRY DRYER DRUM WITH EXTERNAL SURFACE CLEANING MEANS Filed Jan. 15, 1967 fzgwmzw areciegzjcf III III United States Patent O 3,443,323 LAUNDRY DRYER DRUM WITH EXTERNAL SURFACE CLEANING MEANS Frederick W. Grantham, Los Angeles, Calif., assignor of one-third each to Paulette Grantham, Menlo Park, Calif., Frederick Grantham III, Honolulu, Hawaii, and Charles R. Grantham, Los Angeles, Calif.

Filed Jan. 13, 1967, Ser. No. 609,064 Int. Cl. F26b 25/04, 11/04 US. Cl. 3419 Claims ABSTRACT OF THE DISCLOSURE Laundry dryer having an enclosed rotating basket with means manipulable from the exterior for removing accumulated material from the surface of the basket.

CROSS REFERENCES United States Patent No. 2,604,313, issued July 22, 1952, to the present inventor.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to industrial laundry dryers and particularly a laundry dryer having an outer housing and a rotatable perforated basket enclosed Within the housing. The laundry to be dried is placed in the basket, and heated gases are introduced into the housing which pass through the perforations into the basket into contact with the laundry pieces therein and then out of the basket again into the housing from which they are withdrawn to exhaust. In the use of such dryer with certain kinds of laundry pieces made of plastic materials, the plastic evaporates, or partially so, and later condenses and accumulates on the outer surface of the basket in the form of gum. The present invention is directed to removing this gum.

Description of the prior art There is no known prior art relating to the present invention, but the overall construction of the dryer disclosed herein is shown generally in the above mentioned prior patent.

Summary of the invention Heretofore, in order to remove the gum, it has been necessary to stop the rotation of the basket and by some means reach into the interior of the outer housing and scrape oif the gum from the basket, at a serious disadvantage.

A principal object of the present invention is to provide a means that is easily manipulable from the exterior of the housing for removing such gum.

An additional object is to provide means and method for so removing the gum while the basket is rotating.

A more specific object is to provide such removing means, preferably in the form of brush means, such as steel brush means which provides a rigid and stiff instrumentality for so removing the gum.

A still more specific object is to provide such brush means on a shaft which is rockable for moving the brush means into and out of engagement with the basket for removing the gum, to provide means normally retaining the brush means out of such engagement, and to provide an arrangement whereby the shaft can be rocked and 3,443,323 Patented May 13, 1969 BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a front elevational view of a dryer in which the present invention is incorporated;

FIGURE 2 is a sectional view taken at line 22 of FIGURE 1; and

FIGURE 3 is a large scale fragmentary view taken at line 3-3 of FIGURE 2.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now in detail to the accompanying drawings a dryer is indicated in its entirety at 10 which may be of the general kind shown and claimed broadly in my prior patent identified above. However the invention is not limited to such dryer as will be pointed out more specifically hereinbelow. The dryer 10 serving as an example of one form of dryer to which the invention is applicable, includes a dryer proper 12 and a column or structure 14 directly associated with the dryer proper and all preferably incorporated in a single structure. The dryer 12 includes an outer enclosing housing 16 in which is rotatably mounted a perforated basket 18 having an opening 20 exposed to the exterior and closed by a suitable removable cover 21 supported on an arm 24. The cover is movable between closed and open positions by any suitable means. Also the housing 12 with the basket is tiltable on a transverse axis 25 adjacent the front and at the bottom thereof for discharging the laundry pieces from the basket through the opening 20.

The column 14 includes most of the controls and operating devices for the dryer, such as combustion means for heating air delivered into the housing 16 through a duct 22 for example, air moving as indicated by the arrow 26. The heated air enters into the perforated rotating basket 18 and passes through the laundry pieces tumbling therein, and then out of the basket and into the housing 16 where it is carried off through a suitable opening as indicated by the arrow 28. A suitable exhaust blower indicated diagrammatically at 30 may be utilized for this purpose, the exhausted air then being discharged through the duct 32.

Such a dryer is used for drying a wide variety of laundry pieces, including those made of plastic materials that evaporate, or partially evaporate, in the temperatures involved in laundry drying. The evaporated plastic materials later condense on various surfaces in the dryer, including the outer surface of the rotating basket 18, obstructing the perforations therein and impairing the circulation of the air and gases through the perforations into the basket and into contact with the laundry pieces therein. Heretofore it has been necessary to stop the dryer, and by some means reach the surface of the basket and scrape the deposited plastic material, which is now in the form of a gum, from the basket. This was a difiicult operation because it was generally necessary to remove a wall of the housing 16, for example, in order to gain access to the basket.

The present invention incorporates means indicated in its entirety at 34 which is nianipulable from the exterior for so removing the gum from the basket.

The basket 18 includes a cylindrical surrounding side wall 36 (see FIGURE 3) having perforations 38 therein. The gum cleaning means may be any of a number of devices that are effective for scraping or otherwise removing the gum. Preferably brush means 40 is utilized therefor, although other means may be utilized instead, as referred to below. In the present instance the brush means is made up of a plurality of spaced brushes, but a single brush may be utilized instead. The brushes 40 may be of conventional character, each having a backing member 42 and bristles 44, that are strong and stiff and preferably of steel. The brushes are mounted on a rock shaft 46 by suitable means such for example hinge members or straps 48 having one end secured to the backing member 42 by suitable means indicated at 50. The hinge means is mounted on the rock shaft 46 in a suitable manner, such as by friction gripping, riveting, etc., for swinging movement in response to rocking of the shaft.

The rock shaft 46 is journalled in suitable bearings 54 secured to suitable elements of the dryer such as the walls of the housing 16 and the shaft is extended through one wall, preferably the front wall, where a hand lever 56 is secured for manipulation of the brushes. Secured to the shaft is a finger 58 to the outer end of which is connected a tension spring 60, the other end of the spring being connected to a fixed element 62 of the dryer. Collars '64 are mounted on the shaft for engagement with respective journal bearings 54 but preferably spaced inwardly from the bearings to provide for limited axial shifting of the shaft as will be referred to again hereinbelow.

The basket 18 may be, of course, rotated in either direction, such as clockwise as here arbitrarily assumed as indicated by the arrow 66, and the cleaner means 34 is located on the up side of the basket relative to that direction of rotation. The tension spring 60 normally retains the brush means in inactive or retracted position as indicated in dot-dash lines in FIGURE 3, in which the bristles of the brush means are out of engagement with the wall of the basket. When it is desired to remove the gum from the basket, the operator grasps the handle 56 and draws down on it, rotating the rock shaft 46 in counterclockwise direction, and swings the brush means into active or advanced position in which they engage the surface of the basket wall. The bristles 44 being of stiff character, effectively brush or scrape the gum from the basket. The arrangement enables the operator to vary the pressure applied to the brush means to produce a more efficient scraping or brushing operation.

The positioning of the brush means on the up side of the basket facilitates dropping of the gum particles after being removed from the basket, directly downwardly. The invention however is not limited to any exact position of the brush means. Also, it is within the compass of the invention to provide for movement of the brush means to inactive position by gravity, instead of by utilizing the spring 60, if desired.

Normally the perforations in the basket are only provided in the cylindrical wall, and not in the end wall. Therefore the brushes are arranged only for engagement with the cylindrical wall, and are distributed substantially the full axial extent of that wall. Instead of a plurality of smaller brushes 40, a single long brush extending the full axial length of the basket, may be utilized with full effectiveness, but utilizing a plurality of the smaller brushes may be advantageous, as referred to below, and when the plurality of spaced brushes 40 are utilized, the gaps therebetween are effectively obviated by shifting the rock shaft 46 axially, as indicated above, for fully covering the surface of the basket. This can readily be done by merely pushing and pulling on the handle 56.

Utilizing a plurality of smaller brushes may be found advantageous in applying the device to an older dryer originally provided without such device. In such a case a hole of suitable size, and actually relatively small, may be cut in the dryer housing, as indicated at 68 in FIG- URE l, and the individual brushes inserted therethrough and mounted on the shaft, after which a glass window may be used for closing the opening, the opening then providing a window for observing the results of the gum removing operation.

The gum upon being removed from the basket usually is in the form of relatively small particles which upon dropping from the basket, are suspended in the air stream exhausted from the dryer and thus themselves carried out of the dryer.

The brush means may be moved into active position at any time desired, but preferably for example at the end of the day when the dryer is empty so as not to reintroduce any of the gum particles through the apertures into the laundry pieces in the basket. It has been found in tests that the gum accumulated for a full day can be removed in the space of one minute, and this by the simple manipulation of drawing down on the handle 56 while the basket continues to rotate.

Other devices besides brushes that may be utilized for removing the gum are, for example, a blade scraper and a block of wood, and although it is preferred that the gum be removed in the form of small particles that are carried out by the air stream, it is within the compass of the invention to remove the gum in any form such as large particles that fall to the floor and later remove those large particles from the dryer.

I claim:

1. A method of removing accumulated material on the outer surface of a basket in an enclosed housing of a laundry dryer having means for producing an exhaust stream of gases from the dryer, the steps comprising continuously rotating the basket and applying brush means to that surface during the rotation of the basket and thereby removing the material from that surface, maintaining such an exhaust stream while rotating the basket, effecting such removal of the accumulated material in the form of relatively small particles that are suspended in the gas stream, and carrying out the suspended particles from the dryer by that gas stream.

2. A laundry dryer of the character disclosed, having an outer, generally enclosed, housing, and a basket rotatably mounted therein, the outer housing and basket having aligned openings for insertion of laundry pieces to be dried into the basket from the exterior of the housing, and reversely removing them therefrom, the basket having a perforated wall on the outer surface of which materials accumulate, and said perforated wall extending away from the opening in the housing and inaccessible from the exterior of the housing, the improvement comprising, removing means in the housing movable into and out of active position in which it engages said perforated wall, and when in said active position being operative for removing materials accumulated on said perforated wall, the said removing means having an extension on the exterior of the housing, manually manipulable for moving it into active position, the removing means having a normal inactive position out of such engagement and remaining in such inactive position until so manually moved into active position.

3. The invention set out in claim 2 wherein the removing means includes brush means having strong and stiff bristles directly engageable with said surface of the basket.

4. The invention set out in claim 3 wherein the said surface of the basket is a cylindrical surface, the brush means includes members distributed along the length of the cylindrical surface and includes individual brushes spaced apart axially of the basket, and the brush means may be shifted axially so as to fully cover the full axial length of the basket in different position of the brush means.

5. The invention set out in claim 3 wherein the brush means is mounted on a rock shaft extending parallel with References Cited UNITED STATES PATENTS 3/1886 Smith 209-386 8/1905 Klein 55296 3/1925 Brockett 5S295 3/ 1927 Alexander et a]. 34-85 2/1957 Stickel 55289 XR 5 CARLTON R. CROYLE, Primary Examiner. A. D. HERRMANN, Assistant Examiner.

US. Cl. X.R. 

